import 'package:flutter/material.dart';
import 'package:zhiying_comm/zhiying_comm.dart';

class FNNavigatorObserver extends NavigatorObserver {
  factory FNNavigatorObserver() => _getInstance();
  static FNNavigatorObserver get instance => _getInstance();
  static FNNavigatorObserver _instance;

  NavigatorObserver curContext;

  FNNavigatorObserver._();
  static FNNavigatorObserver _getInstance() {
    if (_instance == null) {
      _instance = new FNNavigatorObserver._();
    }
    return _instance;
  }

  String topRouteName = "";

  void didPush(Route<dynamic> route, Route<dynamic> previousRoute) {
    notifyHide(previousRoute);
    notifyShow(route);
  }

  void didPop(Route<dynamic> route, Route<dynamic> previousRoute) {
    notifyHide(route);
    notifyShow(previousRoute);
  }

  void didRemove(Route<dynamic> route, Route<dynamic> previousRoute) {
    notifyHide(route);
    notifyShow(previousRoute);
  }

  /// The [Navigator] replaced `oldRoute` with `newRoute`.
  void didReplace({Route<dynamic> newRoute, Route<dynamic> oldRoute}) {
    notifyHide(oldRoute);
    notifyShow(newRoute);
  }

  void notifyShow(Route<dynamic> route) {}

  void notifyHide(Route<dynamic> route) {}
}